Cushioned cylinder head



June .25, 1946.

L. GREELEY CUSHIONED CYLINDER HEAD Filed May 21, 1 945 Inuenfov heoofireemg ffornegg Patented June 25, 1946 2,402,887 CU H QNED CYLINDER HEAD Leo 0. Greeley, Cadillac, Mich., assignor to General Sales Company or a limited partnership Cadillac, CadiHacQM ich Application May 21, 1945, Serial No. 95,( )l 5 6 Claims. 1

The present inventionrelates to a cushioned hydraulic cylinder. One place where such cyl inder is especially useful is in road scraping equipment, wherein a road surface engaging and scraping blade is movably mounted for raising and lowering, utilizing hydraulic power and pressure to force the blade against the road surface over which it moved. In scraping road surfaces the blade frequently encounters solid obstructions over which it must pass and, therefore, the blade must be lifted in such passage a ainst the hydraulic pressure acting upon it. Inasmuch as liquids are incompressible means must be supplied to permit such lifting of the blade in order to avoid damage or breakage. The present invention provides a very practical and useful mechanism for such purpose.

Furthermore, in the installation of the hydraulic road scraper blade upon a motor truck carrying it, the space available is limited. With my invention the space is reduced to a minimum, the cylinder which is located Vertically being of no greater height than it would be if my invention was not present.

My invention has for its objects and purposes a provision of a particularly effective space saving, practical and durable cushioned hydraulic cylinder construction, one which is readily manufactured and assembled and which is sturdy and durable in construction and capable of fully withstanding the severe conditions to which it is subjected in operation.

An understanding of the invention maybe had from the following description, taken in 9011 1160.- tion with the accompanying drawing, in which,

Fig. 1 is a side elevation partly in section showing the cushioned hydraulic cylinder of my invention.

Fig. 2 is an enlarged central vertical section through the cylinder construction, and

Fig. 3 is a horizontal section substantially on the plane of line 3.. .3 of Fig. .2.

Like reference .characters refer to like parts in the different figures of the drawing.

The cylinder construction includes an outside cylinder I positioned vertically, from opposite sides of which trunnions 2 extend which are mounted for rocking movement at the upper ends of brackets 3 bolted or otherwise connected at the upper side of the substantially horizontal transverse .beam 4 which, in practice, is mounted under the chassis of a motor vehicle and suspended therefrom. At the under side of .the beam 4 a plurality of journal brackets 5 are pe m en l s cu e .t w h whi ,a .rQQk sha 6 extends and on which the scraper element 1 i unted f o king movement, ha in 8 to ctl en a e the road ur a e An arm 9 ex ds from heh ade mountin 1 in the s me.

e t on as t e brack s 3 to th an 9 3 the lowe end or he e tqn'r l L s are c n ct d. .12. n'r d' ente at thel end of e cyl nd r a he ea te de c d.-

The cyli e 1 at i s u pe .endh san rs ai e H wit an nlet a e t et start I? t which a pine a b c nnec ed (Fig- I 3" carr in liquid Pr u e into or for exh u tin l qui at the uppe end o the cyl nde T e 9 e i of the cylinder wh ch nitia l is op n by a lower head It bolted t o an outwardly 1x;- tending flange t t ever and t t e by id The p ton r as s-, thri g the ycad' l and through a con ent qnal stufii s 292; 1.4 t e t leaka i h a i' as an nle and o t ort I? for li lridlrasi ge .ther ti r h il t th art It a d w h. which a eries e or t r rrdu t i cQnntt i- 'h st n od 1 a t u pe end s im lisd with a piston l6 located within an interior cylr i de I? op n a b h end and s h a s H nd". bear ng upo e w si' y e te d ng hoss sc ts the c l r he s. O n c rrrr rrisr iri assa esl i g large areas are provided between the liquid passages at I: and tsndth 'ueneraniq. i e of th inne t li lde fl- The inne 9Y1! 7 having an exterior diameter materially lcssthan t e nteri r chamber 9 th cyli r 1 e is a ncentr c "5953 b ween t e th s sp c kewise at both i s u per an ,lc we d i n ope l rrrirrtlerr wit 1 h.? na ase 'et 1 and r5.

r u -Q -1 21 1 d l we an p tigns f h cylinder 11 a hcavyliji g .20 of located.' The upper ring at itjs'upper side the lower ring at its lower side carrie p ing ring 2| .of leather or other suitable material wh c a er i Place b c r ii rises 5 screw connected to the rings 20. Betw ri he annular pistons .20 a strong ,Omlircssitgri 23 is d p s n rmall t d a c mm which vforces .said 915mm 383 51? the inwardly 3 the bottom of the cylinder the piston I6 is lifted whereupon the road scraper blade is correspond ingly lifted, the liquid above the piston being exhausted through the outlet (2. When the blade is moved to its working position, the flow of pumped liquid is reversed, entering at the upper end of the cylinder to force piston I6 and rod lildown as is evident. After the piston l6 has been moved down to the desired position, or with the desired pressure against it, a valve (not shown) controlling the flow of pressure fluid to and from the passage 12 is closed and therefore the liquid in the cylinder above the piston is trapped. The pressure imparted is heavy in order that the blade 8 may suitably engage and scrape the road surface. Such pressure is also imparted to the upper clamping ring22 thence to the upper ring 20 and thence to the heavy spring 23 which is of sufiicient strength that it will not normally be compressed to any great degree if at all. J ,"When in passing over the road surface the blade 8 comes to an obstruction requiring that the blade be lifted to pass over it, such lifting will move the piston l6 upwardly within. the cylinder 11. The liquid above the piston moved and displaced by such piston movement will thereupon act upon the upper clamping ring 22 and the upper ring 20 with a pressure force of increased amount' causing a compression of the spring 23, the upper ring 20 moving downwardly to provide space for the displaced liquid above the piston I6. The packings 2 t are to seal against the passage of liquid into the space in which the spring 23 is housed. 7

Although the foregoing description and the drawing disclose the device as double ended or having passages between the inner and outer cylinders at both ends with the two annular pistohsZillocated in the outer cylinder whereby the piston 16 may yield under abnormal pressure in either direction it is pointed out that the device may practicably be built and operate as a single ended device.

v In this form there would be no communication between theinner and outer cylinders at one end, as 'for example the lower end, and the annular piston 20 at that end would be eliminated. When so constructed the piston I6 would yield only in a direction toward the end of the device Whereat there is communication between the inner and outer cylinders. g Th'e construction described is very practical, useful, strong and'durable. Itis evident that the vertical height of the'c'ylinder is not: greatly increased. It isa construction which is readily manufactured and assembled. This invention i defined in the appended claims and is to be considered comprehensive of all forms of structurelcomin'g within their scope.

'- V I claim: I

1. .In a jconstruction as described, an outer cylinderhaving closed ends with liquid carrying passages one at each end thereof, an interior cylinder within theouter cylinder spaced therefrom and extending between the ends thereof, said ends of said interior cylinder being open and thespace between said cylinders being open to said liquid carrying passages, a piston within said interior cylinder, a piston rod extending'therefrom, ring pistons surrounding the interior cylinder between it and the outer cylinder, a heavy compression spring between said ring pistons and packings at the outer ends otsaid ring pistons preventing liquid passage past, t y

2. In a construction as described, a vertical exterior piston having closed ends, each end having a liquid carrying passage therethrough from the interior of the piston leading to the outside, an interior cylinder located vertically within the exterior cylinder having its sides spaced from the ides of said exterior cylinder, said interior cylinder being open at both ends and at its ends engaging against .the ends of the exterior cylinder,

said interior cylinder at each end and the space between it and the first cylinder being in freely open connection with said liquid carrying passages, a ring piston surrounding the interior piston adjacent its upper end, packings at the upper end of said ring piston preventing passage of liquid in a downward direction, a heavy coiled spring surrounding the interior cylinder'between it and the first cylinder adapted to be compressed on downward movement of said ring piston, means between said interior cylinder and the exterior cylinder adjacent the lower ends thereof preventing upward passage of liquid to the space between said cylinders, a piston within the interior cylinder and a piston rod extending therefrom through one end of the first cylinder.

3. A construction a described comprising, an exterior cylinder having closed ends, each with a liquid conducting passage from within the cylinder to the outside, an interior cylinder within the exterior cylinder spaced therefrom having open ends, said interior cylinder and the space between the cylinders being in open communication with said passages, movable elements located around the interior cylinder bet-ween it and the exterior cylinder subjected to liquid pressure at the opposite ends of the cylinders, yielding means forcing said movable elements apart, means preventing the passage of liquid past said movable elements to the space between said exterior and interior cylinders, a piston within the interior cylinder and a piston rod connected thereto.

4. An exterior cylinder closed at both ends havin a liquid passage therethrough from the interior of the cylinder to the outside at each end of-the cylinder, an interior cylinder within the exterior cylinder lengthwise thereof open at both end and at its ends engaging against the ends of the exterior cylinder, there being free and open communication between said passages, the ends of the interior cylinder and the spaces between said interior and exterior cylinders, shock absorbing means disposed between said interior and exterior cylinder subject to the pressure of liquid under pressure entered at either end of the exterior cylinder, means associated with said shock absorbing means for preventing the passage of liquid to the interior space between said, interior and exterior except at the ends thereof, a piston within the cylinder and a piston rod connected a movable element surrounding the interior cylin-- der adjacent an end thereof, yielding means normally holding said movable element in a prede-- munication between the inner and outer cylin- 10 6 ders at an end thereof, an annular piston reciprocably mounted in said annular space between the two cylinders, yieldable means for thrusting said annular piston in a direction toward the com- I munica-tion between the two cylinders, a piston and piston rod in the inner cylinder and means for admitting fluid under pressure to said inner cylinder at the end whereat it communicates with the outer cylinder.

LEO O. GREELEY. 

